The company said on Wednesday it will file its application for the line with Canada’s National Energy Board, which regulates intra provincial pipelines.

The filing will be the official start of the regulatory process for the line, which will be subject to an environmental review, hearings and a recommendation from the board to the federal cabinet, which has the final say on whether the project can proceed.

Energy East is TransCanada’s most ambitious project to date. The company, which is also the backer of the controversial Keystone XL project, wants to convert an existing natural-gas pipeline to carry 1.1 million barrels per day of crude as far as eastern Ontario, then add new pipe to Quebec and New Brunswick.

The 4,600 kilometer (2,860 mile) Energy East pipeline will also serve two tanker ports, one on the St. Lawrence river in Quebec and the other at the line’s terminus at Saint John, New Brunswick.